struts2 之文件下載

時間 2019-11-18

原文原文鏈接

1. 文件下載在應用系統使用也很常見。圖片的下載，文件的下載，電影的下載。文件下載能夠很是簡單，經過超連接就能夠直接下載。瀏覽器

<body>
   <a href="download/t.txt">誅仙</a><br/>
   <a href="download/jstl-1.2.jar">struts的jar包</a>
  </body>

可是經過超連接下載有一下問題：jsp

若是瀏覽器可以讀取文件，將會在瀏覽器中直接打開。沒有好的方式來控制用戶是否有權限下載。this

2. 經過流的下載方式能夠解決超連接的不足。實現步驟：spa

a）編寫Action

code

public class DownloadAction extends ActionSupport{
    private String fileName;
    //獲取文件流
    public InputStream getInputStream() throws IOException{
        String path = ServletActionContext.getRequest().getRealPath("/download");
        return new FileInputStream(new File(path,fileName));
    }
    public String getFileName() {
        return fileName;
    }
    public void setFileName(String fileName) {
        this.fileName = fileName;
    }
}

b）配置action:blog

<action name="download" class="cn.sxt.action.DownloadAction">
            <result type="stream">
                <param name="inputName">inputStream</param>
                <param name="contentDisposition">attachment;filename=${fileName}</param>
            </result>
        </action>

c）jsp圖片

<a href="download.action?fileName=t.txt">誅仙</a><br/>
   <a href="download.action?fileName=jstl-1.2.jar">struts的jar包</a>

3.文件下載Action的第二種寫法：get

public class DownloadAction extends ActionSupport{
    private String fileName;
    private InputStream inputStream;
    public String execute()throws IOException{
        String path = ServletActionContext.getRequest().getRealPath("/download");
        inputStream= new FileInputStream(new File(path,fileName));
        return Action.SUCCESS;
    }
    //獲取文件流
    public InputStream getInputStream() {
        return inputStream;
    }
    
    public void setInputStream(InputStream inputStream) {
        this.inputStream = inputStream;
    }

    public String getFileName() {
        return fileName;
    }
    public void setFileName(String fileName) {
        this.fileName = fileName;
    }
}